Machines for buffing sheet material such as shoe soles



g- 15, 1955 c. J. KELHAM 2,715,301

MACHINES FOR BUFFING SHEET MATERIAL SUCH AS SHOE SOLES Filed Nov. 16, 1954 fnuenmr Charles J fT'eZ/zam By his Attorney 2,715,301 Patented Aug. 16, 1955 fifice MACHINES FOR BUFFING SIEET MATERIAL SUCH AS SHOE SOLES Charles John I elham, Leicester, England, assignor to United Shoe Machinery Corporation, Flemington, N. 1., a corporation of New Jersey Application November 16, 1954, Serial No. 469,268

Claims priority, application Great Britain December 4, 1953 4 Claims. (Cl. 51-137) This invention relates to machines for buffing sheet material such as shoe soles, and it is herein disclosed as embodied in a sole bufiing machine of the type illustrated and described in United States Letters Patent No. 2,674,833, granted April 13, 1954, on the application of Peter C. Cheverton and Arthur A. Rivington. The basic machine of said Letters Patent and also of the present disclosure consists of a work table, a buffing roll driven at high speed, a feed roll driven at slower speed, and a spring acting on the feed roll to cause it to press a work piece against the buffing roll. Machines of this general type are in common use for bufling unattached soles of leather or other materials. For simplicity of disclosure the showing of the finger guard which constitutes the novel subject matter of said Letters Patent is omitted herein.

In the bufiing of crepe rubber soles a fairly heavy pressure of the work piece against the bllffing roll is desirable, but such pressure may cause the trailing end portion of the sole to become mangled and torn; the trailing end portion, because of the extreme flexibility of crepe rubher, is apt to follow the abrasive surface of the fast moving bufling roll and to curl down away from the slowly moving feed roll, thereby becoming trapped between the bufiing roll and the edge of the work table immediately to the rear of the bufiing roll. Furthermore, machines of the type above described, as formerly constructed, have also shown a tendency to bevel olf that corner of the trailing edge of a crepe rubber sole which engages the buffing roll.

It is an object of the present invention to provide a sole bufling machine capable of operating satisfactorily upon work pieces of crepe rubber or like material and without damaging the trailing end portions of such work pieces. In accordance with this object, a feature of the invention consists in the provision of a cam arranged to separate the feed and buifing rolls during the feeding of a work piece and before the trailing edge of the work piece passes the bite of the rolls, thereby enabling the operator to withdraw the partially buffed work piece and reverse it, end for end, to complete the operation at the unbulfed end portion.

This and other features of the invention, including certain details of construction and combinations of parts, will be set forth in the following description of an illustrative machine and will be pointed out in the appended claims.

Referring now to the accompanying drawings,

Fig. 1 is a right-hand side elevation of an illustrative machine embodying the invention; and

Fig. 2 is a front elevation of certain parts shown in Fig. l.

The illustrated machine has a rubber feed belt 10 which frictionally engages the upper surface of a work piece to control the feed of the work piece past an abrasive band 12 running over a driven roll 14 and engaging the under surface of the work piece to perform a scouring or bufling operation thereon. The feed belt 10 runs over a driven feed roll 16 and over other rolls suitably arranged. If desired, the feed belt 10 can be omitted, in which case the feed roll 16 should be provided with a rubber cover like that of the feed roll 48 of the machine disclosed in United States Letters Patent No. 2,248,191, granted July 8, 1941, upon the application of John W. Pratt. The rolls 14 and 16 are driven in opposite directions as indicated by the arrows on Fig. 1, the roll 14 which carries the abrasive band 12 being driven much faster than the roll 16 which carries the feed belt 10. The frictional grip of the feed belt, however, holds the work piece from being carried along by the abrasive band and determines the speed at which the work piece is fed.

The roll 14 and the abrasive band 12 together constitute a driven rotary abrading member, and the roll 16 together with the rubber belt 10 constitutes a driven rotary feed member. Work is presented to the machine by an operator who pushes each work piece along a work table 18 until the leading edge of the work piece enters the bite of the driven rotary members above mentioned.

The work table 18 is stationary (except for purposes of adjustment) and is mounted upon a column 20. The abrading roll 14 is mounted on a driven shaft 22 which is journaled in bearings carried by the column 20, the axis of the abrading member thus being stationary and at a fixed distance below the level of the upper surface of the work table, which fixed distance can be varied by heightwise adjustment of the work table. The work table 18 has an opening through which the periphery of the abrading member extends to a level slightly above that of the upper surface of the work table.

The feed roll 16 is mounted on a driven shaft 24 journaled in bearings carried by a pair of side walls of a frame 30, the right side wall being indicated by the reference numeral 28. This frame 36 is pivotally mounted, for rising and falling movements of the feed member 16, 1%, upon eccentric bushings 32 on a shaft 33 rotatable for adjustment in bearings carried by a bracket (not shown) extending rearwardly from the column 29, the arrangement being similar to that disclosed in the patent to Pratt 2,248,191 above mentioned. Secured upon the frame 39 is a cover 34 which does not quite bridge the space between the side walls of the frame and which itself has depending side walls. Secured at their upper ends to pins 36 extending laterally from the side walls of the cover 34 are a pair of springs 38. The lower ends of the springs 38 are anchored to pins as extendng laterally from a pair of arms 42 which are pivotally mounted at their rear portions upon pins 44 extending laterally from the side walls of the pivotally mounted frame 39. The arms 42 are normally held down at their forward portions by latches 46 (only the righthand latch being shown in the drawings) secured upon the work table IS, the pivotal mounting of the arms upon the pins 44 being loose enough to permit lateral movement of the arms as may be necessary to engage them with and disengage them from the holddown latches 46. It is evident from the foregoing description that the feed member 16, 10 is held down by a force resulting from the tension of the springs 38 as well as from the weight of the frame 34! and the parts carried thereby. Downward movement of the feed member under the influence of this force is limited by a stop screw 48 having a knurled head and extending down in threaded engage ment with a boss on the side wall 28. The lower end of the screw 48 engages the Work table 18. By turning the screw 48 the clearance between the feed belt 11) and theabrasive band 12 can be adjusted, and for best results it should be adjusted to a distance a little less than the thickness of the work pieces to be treated.

The machine as so far described is generally similar, except for the right-hand holddown latch 46, to the ready referred to.

The illustrated machine is provided with a novel device for effecting relative separation between the feed and the buffing rolls 16 and 14 respectively to enable the operator to withdraw a sole S from between the rolls after the bufiing operation has progressed from one end (i. e. the leading end) of the sole over half the length of the sole but before the bufiing operation has reached the trailing end. This device comprises a cam 50 (which, as will later be explained, is shown herein as a composite cam) secured upon the right-hand end portion of the feed roll shaft 24. The periphery of the cam 50 engages an idler cam roll 52 journaled for free rotation between upstanding ears of a bracket 53 mounted on a bracket 54. The screws 56 are threaded into tapped holes in the right-hand edge of the work table 18 and extending through horizontal slots 58 formed in the bracket 54, which screws serve to clamp the bracket to the work table with provision for adjustment of the bracket to bring the axis of the cam roll 52 beneath the axis of the feed roll shaft 24 whenever the adiustment of the eccentric bushings 32 is altered. As shown in Fig. l, the bracket 54 takes the place of the right-hand holddown latch of the machine disclosed in said Letters Patent No. 2,674,833 and numbered 46 in that patent.

The corresponding latch of the machine disclosed herein. also numbered 46, consists of a shoulder formed on the bracket 54.

The cam 50 which, as already mentioned, is composite, consists of two disks 60 and 62 mounted side by side on a reduced end portion of the shaft 24 and retained thereon by a nut 64. The cam disk 62 has a hub 66 through which is threaded a set screw 68 having its end engaging a flat on the shaft 24 to hold the disk 62 against turning relatively to the shaft. Each of the cam disks 63 and 62 has a high sector extending approximately 120 around the axis of the feed roll 16 and engageable with the cam roll 52. The disk 60 is rotationally adjustable on the shaft 24 to enable the high sectors of the disk to be brought into register with each other or to provide more or less overlap of the high sectors. To this end there is formed in the disk 62 a plurality of recesses 79 of which any selected one can be engaged by a tapered end portion of a set screw 72 threaded through a tapped hole in the disk 60. As the feed roll 16 turns, the high sectors, reacting against the cam roll 52, will raise the feed roll against the tension of the springs 38 and, by thus effecting a relative separation between the feed roll 16 and the bufiing roll 14, release the sole from the grip of the rolls. The operator then withdraws the sole from between the rolls, reverses it end for end and, as soon as the high sectors have passed the cam roll 52 and the feed roll has descended as far as permitted by the stop screw 48, introduces the reversed sole to the bite of the rolls to buff the remaining unbuifed por tion of the sole.

Soles of considerably difiering sizes can thus be buffed without adjustment of the composite cam 50 if the cam disks 6% and 62 are set to cause the feed roll 16 to effect a feeding movement of the sole of about seven inches, which is over half the length of the largest size soles likely to be encountered and less than the full length of the smallest size likely to be encountered. The

' diameter of the feed roll is live inches and the thickness of the feed belt is and the cam disks can therefore effect a feeding movement of seven inches if they are clamped by the nut 64 with the proper amount of overlap of their high sectors to cause the feed roll to make nearly half a revolution while in its lowered or operative position. For soles of exceptionally large or small size the overlap of the high sectors of the cam disks 6'9 and 62 can readily be adjusted to provide a feeding movement greater than half the length and less than the full length of the soles.

iii

When work pieces are to be bufied from end to end in a single operation without need of separating the feed and bufling rolls, the cam roll 52 can readily be moved to an inoperative position wherein it cannot be engaged by the high sectors of the cam disks 60 and 62. To this end the bracket 53 is pivoted on a pin 74 extending between a pair of side walls of the bracket 54. A screw 76 threaded through the outer side wall of the bracket 54 has an end portion engageable with a recess in the bracket 53 to hold the latter in an operative position wherein the roll 52 is engageable by the high sectors of the cam disks 60 and 62. When the use of the cam roll 52 is not desired, it can be swung back to an out-of-the-way position upon withdrawal of the screw 76. When the cam roll is again swung into operative position, a surface 78 on the bracket 53 engages a complemental surface on the bracket 54 to stop the bracket 53 in position to be locked by the screw 76.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a machine for buffing sheet material, a pair of driven rolls of which one is a bufiing roll and thei other a feed roll, a support for one of said rolls, means acting yieldably on said support for causing said one roll to press a work piece against the other roll, and a cam acting upon said support to move said one roll away from the other roll to release the work piece from the grip of the rolls.

2. In a machine for bufiing sheet material, a bufiiiig tool, a feed roll for controlling the feed of a work piece past the buffing tool, a support for the feed roll,

a spring acting yieldably on said support for causing the feed roll to press the work piece against the bufling tool as the work piece is fed, and cam means acting on said support to move the feed roll away from the bufling tool to release the work piece. 3. in a machine for bufling sheet material, a oufiin roll, a feed roll for controlling the feed of a work piece past the bufling roll, a support for the feed roll, a spring acting yieldably on said support for causing the feed roll to press the workpiece against the buffing roll as the work piece is fed, a peripheral cam secured to the feed roll to turn therewith, an idler roll engageable by the periphery of the cam, and a stationary support in which the idler roll is freely rotatable, said cam being designed to react against the idler roll to move the feed roll away from the bufing roll during rotation of the feed roll.

4. In a machine for bufling sheet material, a bufling roll, a feed roll for controlling the feed of a Work piece past the buffing roll, a support for the feed roll, a spring acting yieldably on said support for causing the feed roll to press the work piece against the buffing roll as the work piece is fed, a peripheral cam disk secured to the feed roll to turn therewith, an idler roll engageable by the periphery of the cam disk, a stationary support in which the idler roll is freely rotatable, said cam disk being designed to react against the idler roll to move the feed roll away from the bufiing roll during rotation of the feed roll, a second peripheral cam disk also engageable with the idler roll, and means for securing the second-mentioned cam disk to the feed roll in face-toface relation with the first-mentioned cam disk with provision for rotary adjustment of the second-mentioned carn disk about the axis of the feed roll, whereby the two cam disks serve as a composite cam for moving the feed roll away from the bufling roll and holding it away over a portion of a complete revolution, which portion can be varied by the adjustment of the second-- mentioned cam disk relatively to the first-mentioned cam disk about the axis of the feed roll.

No references cited. 

